btrfs: move the mapping_set_error() out of the loop in end_bbio_data_write()

Previously we have to call mapping_set_error() inside the
for_each_folio_all() loop, because we do not have a better way to grab
an inode, other than through folio->mapping.

But nowadays every btrfs_bio has its inode member populated, thus we can
easily grab the inode and its i_mapping easily, without the help from a
folio.

Now we can move that mapping_set_error() out of the loop, and use
bbio->inode to grab the i_mapping.

Reviewed-by: David Sterba <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: adam900710

fs/btrfs/extent_io.c

@@ -530,14 +530,14 @@ static void end_bbio_data_write(struct btrfs_bio *bbio)
 		u32 len = fi.length;
 
 		bio_size += len;
-		if (error)
-			mapping_set_error(folio->mapping, error);
-
 		ASSERT(btrfs_folio_test_ordered(fs_info, folio, start, len));
 		btrfs_folio_clear_ordered(fs_info, folio, start, len);
 		btrfs_folio_clear_writeback(fs_info, folio, start, len);
 	}
 
+	if (error)
+		mapping_set_error(bbio->inode->vfs_inode.i_mapping, error);
+
 	btrfs_finish_ordered_extent(bbio->ordered, bbio->file_offset, bio_size, !error);
 	bio_put(bio);
 }